Build list legend
|Version of Microsoft Windows|
|OS family||16-bit Windows|
|Preliminary name||Windows 1.5|
Windows 2.0 is the second major version of Microsoft Windows. It was the first version to introduce support for enhanced features found in Intel's i386 processors. To differentiate it between the 8086-compatible version of Windows 2.x, the i386 version was sold and marketed separately under the "Windows/386" label. Two revisions of Windows 2.x exist, the original revsion (2.0x) in generic "Windows" (8086/i286) and "Windows/386" variants, and a second revision (2.1x) marketed as "Windows/286" and "Windows/386" respectively. It was the successor to Windows 1.0 and was succeeded with Windows 3.0.
As of 2021, no pre-release builds of Windows 2.x have leaked, and some retail versions remain unverified.
Windows 2.0 introduced support for overlapping windows for all window variants, while Windows 1.0 only supported overlapping of dialog windows. This fired a legal conflict with Apple Inc., accusing Microsoft and Hewlett-Packard of violating copyrights Apple held on Macintosh System Software. The judge ruled in favor of Microsoft and HP in all but ten of the 189 patents Apple sued for, which according to the judge couldn't be copyrighted.
This version of Windows also introduced support for VGA (Video Graphics Array) displays and PS/2 mice in the retail release, although drivers for Windows 1.0 have already been available in IBM's OEM release. It is possible to use the PS/2 mouse driver from Windows 2.03 with Windows 1.0, which enables one to use the virtual mouse emulated by many virtualization packages.
Windows/386 is a variant of Windows 2 optimized for the 386 processor. It took advantage of the virtual 8086 mode to preemptively multitask MS-DOS applications, however, Windows itself still uses cooperative multitasking. Each MS-DOS instance is running in a separate virtual machine on top of a 32-bit virtual machine manager, which allows for better compatibility as they no longer share memory space with the rest of the environment. A bigger range of applications can also run in a window as opposed to the original variant, due to Windows/386 introducing grabber files that allow for better video emulation.
A modified version of Windows is running in the so-called System VM, a special virtual machine that controls the VMM and has access to all I/O devices by default. Both Windows and MS-DOS applications could also make use of EMS emulation provided by the virtual machine manager. However, swap is not supported and all running applications therefore have to fit into physical memory.
The original version was renamed to Windows/286 starting with version 2.1, although it does not necessarily require a 286 processor and still runs on the original 8086 and 8088. The separate 386 variant was discontinued with Windows 3.0, which includes its functionality in the 386 Enhanced mode. The new Standard mode also carries over some of the MS-DOS support improvements, such as grabber files.
There is a myth that this version is the first to include the Control Panel, which at one point also appeared on Microsoft's own website. The Control Panel was already included with Windows 1.0 Development Release 5, compiled over 3 years before Windows 2.0 was released.